This invention relates to a mobile radio machine, and more particularly to, a mobile radio machine used as a mobile telephone set or a mobile small computer.
FIGS. 1A and 1B are structural diagrams showing a conventional example of mobile radio machine when its antenna is pulled out and restored, respectively. In FIGS. 1A and 1B, a linear antenna (rod antenna) 91 and a coil antenna 93 at the tip portion, which is exclusively used when antenna is restored, are connected in a line and in a state that each being insulated from the other by an insulating member 92 to compose a whip antenna. Also, a feeding terminal 94 is connected via a matching circuit 95 to a radio circuit 96.
In the above conventional mobile radio machine disclosed in Japanese patent application Laid-open No.8-84017 (1996), when antenna is restored, as shown in FIG. 1A, the feeding terminal 94 is connected to the coil antenna 93 for exclusive use in antenna restored time, and the coil antenna 93 operates, while when antenna is pulled out, as shown in FIG. 1B, the feeding terminal 94 is connected to the rod antenna 91, and the rod antenna 91 operates.
However, in the conventional mobile radio machine, depending upon the size of radio machine, the rod antenna 91 can not be restored in its main body. Also, in the case of a folding type mobile radio machine the rod antenna 91 can not be restored in it.
As another conventional example, such a mobile radio machine is known that a lower antenna and an upper antenna are connected to be foldable at the connecting portion, and when pulling out, the lower antenna is pulled out from the main body to compose a rod antenna with the upper antenna, and when restoring, only the lower antenna is restored in the main body and the upper antenna is tilted through 90xc2x0 from the connected portion composing fulcrum and fixed to an antenna fixing portion on the upper part of the main body (Japanese utility model application laid-open No.4-10408). Also, a mobile radio machine enabled to put a rod antenna element in the main body or pull it outside the main body and rotate such pulled-out antenna to a desired angle is known. (Japanese patent No.2530067).
Also, there is a mobile radio machine in which a linear antenna with long antenna length is enabled to attach to and detach from an connector freely, and in a state that the linear antenna is not attached to the connector, a lay-able type antenna of short antenna length stands uprightly, and when the linear antenna is attached to the connector, the lay-able type antenna is automatically laid in the main body (Japanese patent No.2546922).
Further, a mobile radio machine where a thicker part for the prevention of fall is provided on a part of the main body, and in the thicker part a concave portion capable of receiving a tip of the antenna is formed is known (Japanese utility model application Laid-open No.61-191636).
However, in the conventional mobile radio machine disclosed in Japanese utility model application laid-open No.4-10409 or Japanese patent No.2530067, the lower-part antenna or the rod antenna, though the antenna length itself is shorter than that in former one, is restored in the main body, and therefore the structure is not suitable for a small-size folding type mobile radio machine. In the conventional mobile radio machine disclosed in Japanese patent No.2546923, when using the linear antenna of long length, there is a disadvantage in working efficiency because the work attaching it to the connector is required, and also there is an anxiety that the linear antenna is missing. Further, in the conventional mobile radio machine disclosed in Japanese utility model application Laid-open No.61-191636, though the antenna restoring portion is not provided inside the main body, it is not suitable for a small-size folding type mobile radio machine. Also, the antenna can not function as antenna when it is restored in the concave portion.
Besides, as a conventional mobile radio machine, a mobile radio machine in which an antenna element is enabled to stretch and contract freely, and even when the antenna element is restored, it does not lose the function as radio machine is known (Japanese examined patent publication No.6-12850)
In this conventional mobile radio machine, a feeding point is provided at one position, and when an antenna element is laid, the length is shortened to xcex/4 and the antenna element is used as loop antenna. But, the exact antenna length is not always obtained and varies in some cases. For this reason, a matching circuit connected to a clasp which holds the antenna element when being laid is switched to inductive circuit or capacitive circuit, depending on whether the antenna length is longer or shorter than xcex/4. However, in order to switch the matching circuit connected to the clasp to inductive circuit or capacitive circuit or ground (in case that the antenna length is xcex/4 exactly) according to the antenna length, it is needed to discriminate the antenna length by some method at each time the antenna is laid. Also, the composition of radio machine becomes complicated because, when the antenna is restored, three kinds of matching circuits must be provided corresponding to antenna length and be switched among them.
Accordingly, it is an object of the invention to provide a mobile radio machine with such structure that an antenna can be used even in a folding-type mobile radio machine by forming the antenna to be lay-able type.
It is a further object of the invention to provide a mobile radio machine with simple structure which can be used as radio machine even when an antenna is restored.
According to the first aspect of the invention, a mobile radio machine, comprises:
an antenna including a linear antenna element which is a lower portion thereof, and a coil antenna element which is an upper portion thereof, the linear and coil antenna elements being separated by an insulating member, and the antenna being rotated on a lowest position thereof to take a standing-up position so that the linear and coil antenna elements are exposed to outside of a main body, and to take a laying-down-position so that the coil antenna element is only exposed to outside of the main body, while the linear antenna element is restored in the main body;
a first feeding terminal for making a contact with the linear antenna element in the standing-up position;
a second feeding terminal for making a contact with the coil antenna element in the laying-down position;
a first impedance matching circuit connected via the first feeding terminal to the linear antenna element;
a second impedance matching circuit connected via the second feeding terminal to the coil antenna element; and
a switching circuit for connecting the first impedance matching circuit to a radio circuit, when the antenna takes the standing-up position, and connecting the second impedance matching circuit to the radio circuit, when the antenna takes the laying-down position.
According to the second aspect of the invention, a mobile radio machine with a lay-able type antenna enabled to stand uprightly and be restored in a main body of the radio machine around a rotating shaft provided on a part of the main body, the radio machine comprises:
an antenna which is the lay-able type antenna comprising a first conductive feeding terminal provided with the rotating shaft at its end, a linear antenna element connected at its one end with the first conductive feeding terminal, an insulating member connected with the other end of the linear antenna element, a conductive contact terminal connected with one end of the insulating member, a coil antenna element electrically connected with the other end of the contact terminal and its center axis being located on the extended line of center axis of the linear antenna element;
a switch for detecting whether the antenna being in uprightly standing state or being in restored state;
a second conductive feeding terminal allocated at a position in the main body contacting with the contact terminal when the antenna being restored:
a first impedance matching circuit connecting with the first feeding terminal;
a second impedance matching circuit connecting with the second feeding terminal;
a radio circuit for conducting radio communication; and
a change-over circuit for connecting selectively, when the switch detected uprightly standing state of the antenna, the radio circuit with the first impedance matching circuit and making the radio circuit supply power to the first feeding terminal via the first impedance matching circuit, and for connecting selectively, when the switch detected a restored state of the antenna, the radio circuit with the second impedance matching circuit and making the radio circuit supply power to the second feeding terminal via the second impedance matching circuit.
In the mobile radio machine according to the second aspect of the invention, when the antenna stands uprightly, power is supplied to the first feeding terminal so that the linear antenna element is fed and the coil antenna element, which is electrically insulated from the linear antenna element by the insulating member, is not fed. Thus, when antenna stands upright, only the linear antenna element functions as antenna. On the other hand, when antenna is restored, power is supplied to the second feeding terminal so that the coil antenna element is fed and the linear antenna element, which is electrically insulated from the coil antenna element by the insulating member, is not fed. Therefore, when antenna is restored, only the coil antenna functions as antenna.
According to the third aspect of the invention, a mobile radio machine, comprises a meander-line-like inductance element instead of the coil antenna element in the mobile radio machine according to the second aspect of the invention.
In a mobile radio machine according to the third aspect of the invention, when antenna stands upright, only the linear antenna element functions as antenna. And, when antenna is restored, power is supplied to the second feeding terminal, thereby feeding the meander-line-like inductance element, and the linear antenna element is not fed because it is electrically insulated from the meander-line-like inductance element by the insulating member. Therefore, when antenna is restored, only the meander-line-like inductance element functions as antenna.
According to the fourth aspect of the invention, a mobile radio machine with a lay-able type antenna enabled to stand uprightly and be restored in a main body of the radio machine around a rotating shaft provided on a part of the main body, the radio machine comprises:
an antenna which is the lay-able type antenna comprising a first conductive feeding terminal provided with the rotating shaft at its end, a linear antenna element connected at its one end with the first conductive feeding terminal, an insulating member connected with the other end of the linear antenna element, a conductive contact terminal connected with one end of the insulating member, a coil antenna element electrically connected with the other end of the contact terminal and its center axis being located on the extended line of center axis of the linear antenna element;
a second conductive feeding terminal allocated at a position in the main body contacting with the contact terminal when the antenna being restored;
a first impedance matching circuit connected with at least the first feeding terminal;
a second impedance matching circuit connected with at least the second feeding terminal;
a radio circuit for conducting radio communication; and
a switch for connecting selectively in its inside, when detected uprightly standing state of the antenna, the radio circuit with the first impedance matching circuit and making power be supplied via the first impedance matching circuit to the first feeding terminal, and for connecting selectively in its inside, when detected a restored state of the antenna, the radio circuit with the second impedance matching circuit and making power be supplied via the second impedance matching circuit to the second feeding terminal.
In the mobile radio machine according to the fourth aspect of the invention, when antenna stands upright, since power is supplied to the first feeding terminal, the linear antenna element is fed, and the coil antenna element, which is electrically insulated from the linear antenna element by the insulating member, is not fed. Therefore, when antenna stands upright, only the linear antenna element functions as antenna. And, when antenna is restored, power is supplied to the second feeding terminal and therefore the coil antenna element is fed, while the linear antenna, which is electrically insulated from the coil antenna element by the insulating member, is not fed. Therefore, when antenna is restored, only the coil antenna functions as antenna.
According to the fifth aspect of the invention, a mobile radio machine, comprises a meander-line-like inductance element instead of the coil antenna element in the mobile radio machine according to the fourth aspect of the invention.
In a mobile radio machine according to the fifth aspect of the invention, when antenna stands upright, only the linear antenna element functions as antenna. On the other hand, when antenna is restored, power is supplied to the second feeding terminal, so that the meander-line-like inductance element is fed and the linear antenna element, which is electrically insulated from the meander-line-like inductance element by the insulating member, is not fed. Thus, when antenna is restored, only the meander-line-like inductance element functions as antenna.
As mentioned above, according to the invention, a whip antenna, in which the linear antenna element and the coil antenna element or the meander-line-like inductance element at the tip of antenna, each being isolated from the other by the insulating member, are connected in a line, is used in a form of lay-able type antenna, so that good electrical characteristic is obtained not only when antenna stands upright (i.e., when pulled out) but also when antenna is restored.
Also, in the invention, since the main body of the radio machine is of folding type and its rotating shaft is formed to rotate, when restoring the antenna, in such a way that the antenna is received in a direction parallel to the direction of folding axis, the antenna can be held without incongruity in appearance even in a folding type radio machine.